The present invention relates to systems for managing brake wear on a vehicle provided with brake assemblies.
Brake wear managing systems are particularly advantageous when provided in heavy vehicles since the weight of such vehicles makes braking more difficult and potential loss of control more hazardous than in the case of lighter vehicles, such as for example, automobiles. Routine inspections of heavy vehicles must therefore be done more often to ensure the safety of the driver and of the public. The conventional way to perform the inspection is to visually inspect the brake assemblies.
Routine inspections are however costly since, a) the vehicle must be kept off the road during the inspection, b) a mechanic is required, and c) the wear on one or more brake assemblies can already be too important, resulting in premature wear of the other brake assemblies.
A solution has been proposed by Thorn in U.S. Pat. No. 4,729,214 issued on Jul. 21, 1981 and entitled xe2x80x9cBrake Wear Indicatorxe2x80x9d. Thorn describes a brake wear indicator comprising a sleeve that loosely fits over the push rod of the pneumatic actuator of a truck drum brake assembly. Indicia are calibrated on the exterior surface of the sleeve whereby the inspector can directly observe the degree of sleeve travel that corresponds to the push rod travel in the brake assembly.
Thorn""s system has many drawbacks. For example, the person doing the inspection must know when the push rod travel is unacceptable. This can be seen as a drawback since this visual inspection is based on subjective criteria. Furthermore, the indication is difficult to access and cannot be operated while the truck is running. Finally, since the inspection is based on subjective criteria, it can be difficult to foresee as to when brake adjustments will be necessary, as well as to perform diagnostics.
Solutions to some of these drawbacks have been proposed by Larson et al. in U.S. Pat. No. 5,253,735 issued on Oct. 19, 1993 and entitled xe2x80x9cApparatus to Sense and Annunciate Truck Brake Conditionxe2x80x9d. Larson et al.""s apparatus includes two Hall effect switches that sense the rotation of disks mounted to the S-cam shaft of the braking system. Sensor data are transmitted to an annunciator mounted at a distance from the brake assembly. Separate sensing and annunciating systems are provided for each wheel of the truck.
While some drawbacks of Thorn""s system have been overcome by Larson et al., their apparatus does not allow making any forecast as to when brake adjustments will be necessary. Furthermore, Larson et al.""s system does not directly monitor the push rod. The measure is taken further from the actuating linkage. That can produce less reliable measurements.
Other problems with brake monitoring systems of the prior-art include the difficulty to manage brake changes for fleets of vehicles since they do not allow remote monitoring of vehicles and the fact they don""t provide any visual tool to assess the operating performance of their sensors to help identify problems of the brake assemblies.
An object of the present invention is therefore to provide a brake wear managing system free of the above-mentioned drawbacks of the prior-art.
More specifically, in accordance with the present invention, there is provided a brake wear managing system for a vehicle provided with at least one brake assembly, the brake wear managing system comprising:
at least one sensor assembly including a sensor and a mounting assembly to secure the sensor to one of at least one brake assembly; each sensor being so configured as to generate a signal responsive to brake wear; and
an on-board controller coupled to each sensor; the on-board controller being configured to receive said signal from each sensor and to generate brake wear condition signals accordingly.
According to a preferred embodiment of the present invention, the brake wear managing system further comprises a remote controller coupled to the on-board controller and being configured to receive at least one of a) the sensor signals and b) the break wear condition signals. The remote controller is so configured as to generate break wear history database.
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.